Published European Patent Application No. 0209070 of Param J. Singh discloses a high-frequency intra-arterial cardiac support system in which a balloon pump is positioned in a major artery downstream of the heart and is cyclically inflated and deflated at a frequency at least three times that of the normal heartbeat. When inflated during diastole, the Singh balloon pushes blood through the coronary artery. During systole, however, the high impedance of the coronary artery essentially eliminates this effect while the body is being actively perfused.
The Singh balloon does not actively perfuse the body when it is deflated during diastole, as its deflation does not cause any suction through the aortic valve. In order to achieve good myocardial preservation, it is however important to decompress the ventricular cavity during diastole, i.e. to create suction through the aortic valve by the operation of the cardiac assist device.